I think the main thing is that on most of the major national carriers here in the US, it's cheaper to either pay your parents (or someone else) your portion of

I think the main thing is that on most of the major national carriers here in the US, it's cheaper to either pay your parents (or someone else) your portion of the line on the family plan (usually $9.99 + data plan), or in the case of the new share plans, $30-$40 for a smartphone. Compared to setting up your own individual plan which would cost even more. Now, from experience, my sister (36) only just got off my parent's family plan this June. I myself (22) do not plan on getting off my parent's Verizon plan anytime soon because I want to retain unlimited data as long as it's available. If it does get to the point of where they want be off their plan, I will have to go with T-Mobile or another pre-paid carrier because there is no way in hell I will pay $100/month with Verizon just to have a single smart phone.